Heart disease is a critical healthcare issue for the individual patient and for society as a whole. Recent research has shown that treatment of heart disease, when guided by improved diagnostic methods such as functional assessment of the coronary circulation using intravascular pressure measurements, leads to both improved quality of life for the patient and reduced healthcare costs for society.
Intravascular catheters and guide wires are commonly utilized to measure the pressure within the blood vessel, to visualize the inner lumen of the blood vessel, and/or to otherwise obtain diagnostic information related to the blood vessel. To date, guide wires containing pressure sensors, imaging elements, and/or other electrical, electronic, optical, or electro-optical components have suffered from poor mechanical performance in comparison to standard guide wires that do not include such components. Existing pressure-sensing guide wires typically incorporate a single pressure sensor located approximately 3 cm from the distal tip of the guide wire. Since the sensor is fixed in position on the guide wire, the pressure can only be measured at different locations within the vasculature by advancing or retracting the entire guide wire to position the sensor at the desired location. Traditionally, the pressure-sensing guide wire includes a sensor formed on a planar substrate and having terminals attached to the conductors of a cable which runs through the intravascular device. The sensor substrate is typically oriented such that the pressure sensitive portion faces radially outward into the blood stream. It is generally desired to separate the substrate slightly away from the walls of the intravascular device in order to mechanically isolate the pressure sensor substrate from the guide wire structure, so that bending and torsional stresses are not coupled to the sensor substrate where they could adversely affect the pressure measurement accuracy. This pressure sensing guide wire geometry provides access for intravascular pressure measurement, but results in compromises to the mechanical structure which lead to poor mechanical performance compared to that of a conventional guide wire without measurement capability. Furthermore, the fragile electrical interconnects between the sensor terminals and the electrical leads are vulnerable to failure. In this conventional configuration the small diameter of the intravascular device introduces places constraints on the sensor dimensions, exacerbating the limitations and associated problems.
Accordingly, there remains a need for improved intravascular devices, systems, and methods that preserve the desirable mechanical properties of the device while providing a more robust interconnect to one or more electrical, electronic, optical, or electro-optical components.